1. Joker... just Joker. Not only is he scary, he is unpredictable, smart, and UTTERLY INSANE.
   
   2. The Brethren Moons from Dead Space. They don't have an active role, at least for the most part, but they are moon sized conglomerations of millions of tons of dead flesh, with the combined intelligence of all of that flesh, and are hell bent on literally devouring all living things in the universe. THEY HAVE WIPED OUT EVERY SINGLE SPECIES IN THE GALAXY EXCEPT HUMANS.
   
   3. Fanfiction-styled Sakura Haruno from Naruto. If that doesn't count, then Ice King from Adventure Time.
   
   4. Andrew Ryan. He was an a**hole, sure, but he had a dream, and he saw it through, even as it came crashing down around his ears. And then his city is usurped by his worst enemy. And then a not-so-worst-enemy right after.

Hmm...

1. Makishima Shougo from Psycho-Pass. In the show, a vast computer network called the Sybil System more or less dominates everyone's lives (and in fact determines what job you should go into). Makishima is out to destroy it, and he does so at least partly by taking advantage of people's dependence on the system. (See, for example, the scene where he kills Akane's best friend after her Dominator fails.) This guy never loses his cool, quotes classic literature (including the Bible at one point), and takes no prisoners. Sociopaths make great villains, huh?

2. The Autons. Mannequins look creepy enough without being under control of an alien hive mind. Especially not when said hive mind can extend to a trash can and somehow replace Mickey with one of them. (Also the hound from "The Hounds of Baskerville" even though we never actually see it.)

3. [no data]

4. Hmm, probably Grovyle from Explorers of Time/Darkness/Sky. He steals the Time Gears, which is a pretty Bad Idea, but it's all to fix up the future. Plus, he used to be the protagonist's partner back when he/she was a human, so he can't be all that bad. (You can tell I haven't gotten to that part of the story in a long long time.)

I think best villain is Xanatos because he rarely lost. Though at lot of the time it was a technicality of plan G still having a favorable outcome. Except half of the time his schemes weren't that evil despite what happened when they were evil. It's like he would use his powers for good if he had more of a conscience and was only motivated by boredom instead of the will to win.

I'd like to include Turbo as a best example of a villain. He has pure thoughtless greed as his motivation, and uses a variety of ways to be evil. (He seems to have more charisma than Hitler.)

I used to be afraid of Mum-Ra when I was five. The cloners from Star Wars bothered me because they loved making weapons, but they aren't villains. I guess I'll say the Borg because they were just coldly efficient and you couldn't even argue with them; and I don't really watch anything scary.

Jumba from Lilo and Stitch is least effective because he seems like his heart isn't into villainy. He just wants to be known as an evil genius, (and his hobby happens to be illegal and dangerous without mention of if that's why he chose it.) But he got distracted because saving the day was more interesting at the moment.

Wreck-it-Ralph is sympathetic, but he's not a villain because it's his job. It's like hating the garbage man because he stinks. Silver from Treasure Planet has a soft spot and gets sympathy in return even though he did kill. I do like realistically-motivated villains but can't think of the best example. Lurky from Rainbow Brite does it because his mother yelled at him and she never explained what she meant.

I'm disappointed that I couldn't shoehorn a Tony Jay villain like Frollo in here.

I'll try to keep this as spoiler free as possible, even if the properties involved are older.

1. Handsome Jack (Borderlands 2). The thing that impressed me about Jack the most was how well he covered the gamut of villainy over the arc of the game. He starts out as a smug and rather petty jackass, calling you just to brag about how awesome and wealthy and clever he is and how much you suck. He's simultaneously infuriating and hilarious.

BUT THEN the first twist occurs. Turns out Jack is almost exactly as clever as he says he is: he not only manipulated you, he manipulated the main characters of the first game as well. Everything has gone according to his intentions so far. His gloating intensifies, but now the player starts getting a fuller picture of how nasty and sadistic he really is.

BUT THEN the second twist occurs. You see the extent to which he's willing to go to achieve his vision, and it is fairly frightening. You do something that Jack takes EXTREMELY personal. His messages are still humorous, but now the barbs he flings at you are more pointed and cruel. He wants you dead, but at his own hands. He threatens the lives of any who would kill you and thus deprive him of his vengeance.

And then finally, to complete the villainous sweep, he has his final breakdown rant at the end of the game. In his own twisted mind, HE was the hero of this story. So to see you triumphant over him... he just doesn't get it.

HONORABLE MENTION - David Xanatos (Gargoyles)

2. Judge Doom (Who Framed Roger Rabbit). I'll admit: this one is all nostalgia-based. Doom was the one villain I can remember from my childhood that terrified the hell out of me, even before the big reveal at the end. I don't spook as well now, but the last time I saw him still set the hairs on the back of my neck on end. His demeanor and appearance, even the way he moves, almost felt uncanny valley-ish.

HONORABLE MENTION - Hannibal Lector (Silence of the Lambs)

3. Amon (The Legend of Korra). A charismatic and manipulative speaker. A fighter who could outclass any Bender, even the Avatar. A master tactician whose henchmen were superior to the armed forces. Amon was so competent at everything, he became boring. I'm not interested in a villain who can curb-stomp any and all comers until the finale rolls around. I like heroes and villains who are capable of failure. Failure makes them human. Failure makes them relatable.

DISHONORABLE MENTION - Cersei Lannister (the original version of her from A Song of Ice and Fire; the television Game of Thrones version is rather more sympathetic)

4. The Ice King (Adventure Time). He started out as a joke. A pathetic and easily-thwarted dope who kidnapped princesses and didn't really seem all there. But then "Holly Jolly Secrets, Part II" came out, and we discovered WHY he was like that. Suddenly he didn't seem as funny anymore. And it only got worse from there, what with his interactions with Marceline. There's a scene in of the the written comics where the Ice King is trapped in his greatest desire by the Lich. Finn and Jake have to break the illusion by destroying that which he has always wanted. And it is... rough to read.

HONORABLE MENTION - Mr. Freeze (Batman: The Animated Series)

1) don't know about best villain ever, but one of my favorites is the Joker. No matter how crazy and insane he made be, he is the perfect anti-thesis for Batman. And we all know how good Batman is...

2) Don't know about most terrifying, The Queen Of Blades. Besides the scary appearance and utter destruction she causes, the fact that as both a gamer, and as Raynor in game you know exactly who she was before she became the Queen, and the fact that, as the gamer you controlled her on that mission that lead to her becoming what she is (even if you put a solid few lines of bunker's siege tanks and missile turrets the zerg still overwhelm you). And that somewhere beneath all of it is still Sarah Kerrigan. It gives me the shivers.

3) Not quite a standard example, but in Dragon Age Origins: Awakening a side quest reveals that some bandits have kidnapped a nobleman's daughter and he wants you and your group (who are all quite badass by themselves) to get her back. Arrive at the bandit camp (which, is situated on the edge of a cliff. (Note this for later)) and the bandit leader will talk to you. You get a couple of lines back, where you can reveal yourself as the Commander of the Grey (note this means you've killed hundreds of monsters, demons, bandits etc. And an Archdemon that used to be an old god (and is also a dragon)). The next time you get to choose a speech option there's an intimidate option, pick it and half the bandits run away, including one who decides to jump off a cliff instead of facing you. Or you pick the persuade option which means they give you the girl BEFORE you give them the money. Either way much bandit killing ensues. I think they win the prize for stupidest villains if nothing else.

4) N, definitely N. He's been bought up, only being raised around Pokemon who have been badly treated by their trainers and thus wants a world where those kind of Pokemon don't suffer, however due to his father's manipulations he thinks all trainers are like this to their Pokemon. The whole plot line with N in both Black/White and Black 2/White 2 are the best plots in the whole of the Pokemon series IMO and the end scene of Black is the only time in the main series I've ever let out manly tears. (PMD has about one per game for me otherwise)

Now this will naturally be spoiler-y, so here we go.

1) Kerghan the Terrible (Arcanum: Of Steamworks and Magick Obscura)
From a certain point of view Kerghan is not actually a villain.
He's spent his two thousand years in banishment meditating on life and death, along with some practical experiments (he was, after all, the one who discovered the Necromantic Black school of magic) and finally came to the conclusion that the afterlife is preferrable to normal existence.
What makes him a threat is his desire to show everyone by killing everyone and his utter blindness to other views (unless the player happens to possess a Master rank in Persuasion, compare: Fallout.)
So why is he, as I've stated, not necessarily evil?
That is because he is right. His research on the state of the afterlife is correct, two party members (one undead, one resurrected) can confirm this. His work, should he succeed, will also result in the liberation of all undead souls from their host bodies, which is considered quite merciful given the universe's description of the undead (a soul torn from the world of the dead and forced into a body - even an animal carcass - that has just barely been restored to working order.)
It should be noted that the player is given the option of assisting Kerghan in completing his goal. Doing so will, however, render most morally "good" party members hostile and willing to fight to the death.

2) Tough one to decide, but it will have to be SHODAN.
What she has managed to do to all life within her reach borders on Reaper territory - and instead of a collective of who-knows-how-many-thousand species, each consisting of billions of individuals harvested and processed she was just one AI. One computer system turned rogue, managed to get awfully close to godhood, survived two purges (one by cyberjack, the other by bullet) and is still around if the second game's ending is to be believed...although I somehow have little hope to ever see System Shock 3.

3) The Catalyst. It's when Mass Effect stopped making sense. The Reapers were supposedly designed to protect all sentient life from exactly the same kind of phenomenon that they themselves are. It makes very little sense - and making sense should be what advanced AIs ought to excel in.

4) Again, a very tough one. But I sympathise very much with Nightmare Moon.
She is a phenomenon resulting from fear of rejection, which she herself rejected. I assume self-pity factored in, envy certainly did.
She became vindictive, aggressive and potentially delusional. It is likely that she would refuse any help given and any kindness shown as she views the world as hostile.
She was clearly proud of her unwavering loyalty to her own beliefs, incorrect and harmful as they are. After all everyone else abandoned her, so why should she not believe in herself?
Overall she shows flaws that I can relate to, the presence of which I can feel within myself.
Arrogance.
Contempt.
Pride.
Envy.

These are probably not my Ultimate Answers, because there are so many things I know I'm not thinking of, but it's something.

1. My favorite villain is Scorpius from Farscape. He's brilliant, well-spoken, ruthless, and incredibly disciplined—when he looses his cool, you know it's time to run away really, really fast. And that's not just an expression. Being a hybrid of the cold-loving Sebacean race and the heat-generating Scarran race, his own body is constantly at war with itself, and he has to wear a cooling suit with a cooling rod that goes right into his brain to keep from overheating. The fact that he overcomes this physical difficulty with little to no help and manages to work himself up into a position of power in the notoriously xenophobic Peacekeeper military shows you exactly the kind of determined genius you're dealing with when Scorpius is in the picture. He never wastes energy, he is always charming (well, almost always), and he gets things done. He is just awesome.

2. My first thought for this one was Judge Doom from Who Framed Roger Rabbit? He's crazy, he puts that poor little cartoon shoe in the Dip (scarred me for life), he looks somehow wrong the whole time and then his whole body melts off and his eyes pop out and HOLY CRAP AHHH. He's classic wet-your-pants scary.

I also thought of the guy from Red Dragon, whose name I can't remember right now. Anybody who murders his family pets is horrifying. Not to mention the many other disturbing things in that book, which I can't even remember because my brain has blocked them out. (That whole book is psychologically disturbing. This is the whole point, though. I recommend it!)

3. Least effective villain I can think of is what's-her-name from Divergence. You know, the blonde Erudite lady who decides her caste is best fit to control the others, being so smart and all, and then gets foiled by a couple of kids who joined the caste famed for being brawny and reckless. Her plan was stupid, her reasons for coming up with it in the first place were stupid, and literally all I can remember about her is thinking how stupid she was.

4. I'm not sure I can properly articulate this one, but all I can think of for most sympathetic villain is the Lone Power from the Young Wizards series. It's tricky because He* is literally the Devil, and every other Being of Ultimate Evil you've ever heard of. He's the guy who invented pain, suffering, and death, and He spends His time tempting newly formed intelligences over to the ways of entropy so as to speed up the end of the Universe. But... He had a good reason? Entropy is why we have time. Death is why we appreciate life. Pain and suffering are what drive us to create, so we can overcome them.

And the thing is, His siblings, the other Powers That Be, They want Him back. The fact that They rejected Him in the first place is half the problem. They didn't like His ideas, so He went rogue and forced them on Creation anyway, so things are really screwed up—but they don't have to be. The PTBs and the One (read: God), who give the wizards their power to fight the Lone One, don't want Him destroyed, They want Him redeemed. And so do I.

* Technically all the Powers That Be are genderless, and usually referred to as It, but that's kinda weird. And so is capitalizing all the pronouns, but oh well.

~Neshomeh

1) Sovereign, from the Mass Effect series. Listen to this. Thar be spoilers beyond that link, so... yeah.

2) Carcer Dun, from Terry Pratchett's Night Watch. There is no redeeming the man: he sees all the rules we make up in our society to keep our darker impulses in check and just decides to not follow them. He is a psychotic mass murderer and the most chilling thing about his character is the fact that he's completely detached from the crimes he's committing; it is said that Carcer can savagely stab a person to death in front of a crowd and behave like a totally innocent person when confronted. What distinguishes him from some other person playing dumb is that Carcer sees his actions as just being "naughty". He has no restraints. He has no morals. He is the embodiment of chaotic evil. Carcer provokes a visceral reaction of disgust from the reader, even if it's the zillionth time you read the book.

You will love to hate him.

3) King Sombra from My Little Pony: Friendship is Magic. Let's face it: he was a laughing shadow for most of the episode. Not exactly threat material if you ask me.

4) Bowser, from Super Mario Bros. I mean, sure he kidnaps the princess every now and then, but he plays sports and go-carts with you on his days off. He even loans out his castle as a race track. Unfortunately, whenever things seem to go well for him, bad things (read: hilarious antics) start happening to the Koopa King. All in all, he's a pretty cool dude if you ask me.

1: Definitely Arvis, of Fire Emblem: Genealogy of the Holy War. Well, actually it's probably Manfroy, the guy behind Arvis's plots, but Arvis actually kills the protagonist. And brainwashes and marries said protagonist's wife. Who happens to be Arvis's sister. Arvis then presides over a regime that kidnaps children and forces them to fight to the death; the survivors become 'aristocracy' under the thumb of the Loptyr sect. Mind, Arvis's son Julius is even worse, due to being the physical body of the evil god Loptyr; this guy kills his mother while trying to kill his sister.
2: Most terrifying? Not entirely sure, but all the people on my shortlist are Hero Killers. There's Findo Gask, from the Word and the Void series, who is ruthless with his followers and tenacious as anything, not to mention clever. And Badrang the Tyrant, of Redwall (the series, not the book); bastard killed Martin's girlfriend Rose and had Martin the Warrior himself captive. Then there's Lysandre, from Pokémon X and Y, who literally attempts genocide to make the world 'beautiful'.
3: I don't know whether they count as a villain, but Doctor Who's Weeping Angels in everything but Blink are just... not scary at all. Which is a shame, really.
4: Easy: N Harmonia, of Pokémon Black and White. He's not even really a villain, just an antagonist. He basically intends to conquer the region with a legendary Pokémon in order to command people to release their Pokémon, because he believes all people treat Pokémon as slaves. He gradually comes to realise that there are other people who treat Pokémon with respect and love, and is on the verge of stepping down when his father, the Complete Monster Ghetsis, comes along and reveals that he'd been manipulating N from birth, only showing him Pokémon who had been abandoned by horrible people. Ghetsis's plan was to have N order everyone to release their Pokémon, then dispose of him and rule the region by being the only one who still had Pokémon.
Others include Fëanor (he's nowhere near heroic, but he was mad with grief, so understandable), Lyon of Fire Emblem: The Sacred Stones (who loses his father and receives a prophecy that his country will be ravaged by an earthquake, and accidentally becomes possessed by an ancient demon king while trying to reverse the former and avert the latter. Oh, and he's in love with the heroine but can't compete with her brother for her love) and Ontic Laison (to a lesser extent; she killed Imbolc Telyan, which makes me hate her, but she did go through some pretty bad stuff).
Gee, sympathetic villains are just crawling out of the woodwork. I could go on, but that's enough, I think.

1) Whatever overlord put together the list if 'Things I must not do if I am an evil overlord' list. Wait, that doesn't count? Hmm... If I ever find a villain who does the sensible things and kill the hero immediately instead of sentencing him to a slow death by a watery pit of hungry crocodiles armed with lasers and then stand there and laugh, saying 'Escape is impossible!', then that's the one I vote for.

2) Fenrir Greyback from Harry Potter. Not only is he a sick cannibal whose favorite targets are children, but he also gives this 'I'm going to rape you' vibe. I still sometimes have nightmares about him.

3) The Grunts from any Pokemon villain team. Usually when the player storms the team's secret headquarters, the Grunts will randomly tell you important information after you beat them and are sometimes insanely stupid. Best example would have to be in X/Y when you're about to clear out the Kalos power plant and need a key to get in. The Grunt blocking the way says something like "Oh no! I've dropped the key! I think I last had it when I was standing nine steps east of where I am now! Maybe if I used the Dowsing Machine, I could find it!"

4) Megamind. He tried so hard to be bad, but he was kind of... bad at that. I want to give him a hug. :)

1) Syndrome (The Incredibles)- even if he didn't read the Evil Overlord List, he's still pretty darn good at it. He builds a nigh unbeatable robot by testing it on superheroes, and threatens to steal Mr Incredible's son out of pure bitterness and hatred.

2) I can't honestly think of anybody at the moment. But the traits I look for in a scary villain is not necessarily being stronger than the hero. It's the unpredictability and single-minded devotion to a cause. Also, superior strategy. Nothing is worse than a villain with a Batman Gambit.

3) Starfinger (Legion of Superheroes TV series)- seriously? The man is completely incompetent. His powers would actually be useful if he utilized them properly, but… The dude's a weirdo with a really bad accent.

4) Megamind (Megamind)- Watch the movie. The whole plot is how he's actually a sympathetic bad guy who realizes that he doesn't want the role that the rest of the world has put him in. Do watch the movie. It's hilarious.

Villainsvillainsvillainsvillains--ahem. Warning. Fan ranting ahead.

1. Gabriel Gray/Sylar (Heroes)
This dude . . . is just awesome, yo. When he was first introduced in season one, all we were shown were the gruesome and physics-defying results of his murder scenes. We never even saw him closely for the entire first half of the season--he was just a figure in shadows, throwing stuff and people through the air with a flick of his hand. When we finally did meet him, he had a creepy, intense stare and a slightly gravelly, creepy voice. Zachary Quinto used these to great effect and combined them with an obsessive, disturbing curiosity in his performance to drive home the hunger that lay behind Sylar's character: He wants to see how you work, and he's going to open you up and examine your parts like a clock to do it. he also had a really awesome theme song background sound effect of ticking clocks to underline the twisted function of his mind. Sylar is very much the driving force of season one's plot, to the point where he essentially hijacks another plot to turn himself into the final challenge for the protagonists at the end of the season.

Heroes suffered from a good deal of shoddy writing, and in later seasons began irritatingly waffling back and forth between flirting with redemption and going back to being stone-cold insane and evil. But despite all of that, he still stayed awesome. He frequently beat the snot out of the villains of future plot lines, as if to remind the universe how awesome he was. He's both smart and insane, manipulative and brutally forceful, and is pretty much the best character on the whole show.

2. Human!Yawgmoth (Magic: the Gathering)
Yawgmoth spent most of his character career as the unseen lord of Phyrexia, a land of organisms composed partly of machinery and partly of undying flesh. The Phyrexian armies were entirely devoted to Yawgmoth, and single-mindedly carried out his plans to spread glorious machine compleation (not a typo) throughout the entire multiverse. When Yawgmoth finally appeared on screen, he was revealed to be a sapient black cloud of death, swiftly flowing across the plane of Dominaria to choke out all the imperfect life and fold it into himself.

None of that makes Yawgmoth particularly terrifying; it's pretty par for the course with dark lords in fantasy settings. Yawgmoth is terrifying because of his behavior as an ostensibly normal human during the prequel novel The Thran. Yawgmoth's behavior as just as monstrous as a human as he would later be as a monster--but it's all the more terrifying because he is presented as just a regular human with some very, very sick ideas. After being attacked by a bear and receiving an injured arm, the mage who heals him has to chide him for poking around the wound and infecting it. He responds by saying that he couldn't pass up the opportunity to study human body parts. Already, he was looking at living things as parts. (An older version of the story, which I believe is unfortunately no longer canon, had him remove sinews and tendons from the bear's arm to replace his injured ones.) Yawgmoth is all about upgrades, you see; when he learns about the existence of planeswalkers (super-wizards who don't age), he captures one and has some of minions peel open her body one cubic meter at a time looking for the one special thing that made her different, so that Yawgmoth could insert it into himself and become more powerful. One line summarizes Yawgmoth's entire character: after months of striving to fight a plague (which it's heavily implied that he created and spread in the first place), he felt that the people he had helped weren't acting respectfully enough. When the leader of those people chided him for his ego, saying that Yawgmoth was a healer, not a god, Yawgmoth replied, "After everything I have done for these people? They had damn well better treat me as a god."

Yawgmoth was an ordinary man who believed he deserved godhood--and he made it happen.

I'm going to get major flack for this one, but
3. Professor James Moriarty (The Final Problem
Yeah, I know, it's Moriarty, but bare with me. Most of what you think about Moriarty comes from later adaptions of Holmes stories, like Sherlock or even The League of Extraordinary Gentlemen. But the original Moriarty? Is basically a non-entity when seen through the lens of the entire, original Doyle canon. If I may be uncharacteristically crude, Moriarty was basically an asspull of Doyle's part as part of his attempt to kill off Holmes and move on to other writings (which I'm not criticizing; it was his right to do so). Moriarty is thrown into the story just to be killed off and take Holmes with him. He is shown to have high intellect, like Holmes, and good fighting skills and strength, like Holmes. But because he never shows up in any other story, all that info basically just rings false; it's too much "tell, don't show" and it makes for a rather impotent and forgettable villain (again, looking only at the original canon which is all that exists).

4. Seymour Guado (Final Fantasy X)
This is an opinion that I've only developed recently. Back in high school, all my FF fan friends and I hated Seymour (and I'm embarrassed to admit, a lot of that was childish, group-of-males reaction of, "Ew, he's so effeminate, why doesn't he put on a shirt and also speak several octaves lower). Recently, though, I've thought about his goals and motives more, and I find myself a lot more understanding of his position.

The setting of FFX in a nutshell is: "A giant whale pops out of the ocean and obliterates entire cities, but sometimes a special summoner goes and beats the whale up and makes it leave us alone for two or three decades." What the majority of the populace doesn't know is that every time that happens, the summoner is sacrificing someone they love, which then becomes the new whale. The original summoner, who started that whole summoner religion, was using the sacrifices and their giant whale body-thing-whatever as a protecive vessel, using the people's reverence for himself to keep himself alive forever, and using what everyone thought was salvation and safety to perpetuate their destruction.

Seymour was a summoner, and sacrificed his mom to fight the whale--except he never tried to fight it. Instead, he looked at the endless cycle of death and temporary peace in his world, and he saw only one hope, one way to end the suffering: kill everyone in the world. With everyone on Spira gone and unable to worship, the whale and the original summoner would die, too, finally ending the cycle. To do this, Seymour saw that he had to sacrifice himself to another summoner to become their summon, allowing him to take control of the whale and obliterate the world and everyone in it. It's absolutely insane, and he committed at least a few murders along the way, including his own father (and one near-genocide!), but in a world where the greatest hope is, "maybe this most recent human sacrifice will get us three whole decades before the giant whale inevitably rises out of the sea and destroys entire cities again!" Seymour sought escape and piece for everyone. And while that wasn't the only way (the player party obviously fixes everything in the end), Seymour lived in a society almost completely dominated by the rhetoric of their faith, and it's hard to blame him for being unable to see beyond what he had taken for granted since he was a child.

He still has an annoying voice, though.

Well, not as annoying as Tidus's.